Apparatus for prefabricating building walls

ABSTRACT

Apparatus for assemblying prefabricated building wall panels from individual components including sills, plates and studs. The apparatus positions the components relative to one another and automatically joins them together as they are moved forwardly through the apparatus. Provision is made for accommodating studs of unequal length and for incorporating preassembled window and door frame units in the wall panel.

[451 Mar. 25, 1975 United States Patent [1 1 Whitaker Heferick, Jr.

[ APPARATUS FOR PREFABRICATING BUILDING WALLS Primary ExaminerGranville Y. Custer, Jr.

Attorney, Agent, or Firm Fitch, Even, Tabin & Luedeka 4 5 X 0 B 2 n 6 n7 e3 an t n .me WT mm wk of. PB O t n e V n 1 N 7 [22] Filed: Jan. 2, 1974 App]. No.: 429,755

[52] [1.5. 227/7, 227/44, 227/100 Int. B27f 7/02 227/5, 6, 7, 39, 44, 99,

[51] Field of Search.............

nents relative to one another and automatically joins 227/100, 101 them together as they are moved forwardly through the apparatus. Provision is made for accommodating [56] References Cited studs of unequal length and for incorporating preas- UNITED STATES PATENTS sembled window and door frame units in the wall panel.

227/44 X l 1970 M t' 227 44 X 12l1971 M m 22/7/1O0 5 Claims, 9 Drawing Figures 3,370,769 2/1968 Price, 3,489,328 3,628,714 Offenwanger.......................

MENTEUMAMSIQIS 1873,01?

SHEET 7 if PRESEURIZED l 290 I PRESSURIZED AIR 296 245 246 284 222 240 286 PRESSURIZED AIR APPARATUS FOR PREFABRIGATING BUILDING WALLS This invention relates to apparatus for assembling prefabricated wall panels from individual components including sills, plates and studs. Provision is also made for incorporating window and/or door frame units into the wall panel.

A common building wall panel includesa sill, a plate and upright studs disposed between the sill and plate. Two by four lumber is commonly used as the sills, plates and studs, these components being joined together by nails. It is advantageous under certain circumstances to prefabricate a wall panel at a location away from the building site and thereafter move the panel to the site for erection. In many instances, it is desirable that the panel include framing units for one or more windows and/or doors. Such framing units generally comprise two upright studs having upper and lower cross members nailed between them to outline an opening for a prefabricated window or door. The length of the cross members and their vertical spacing are dictated by the size of the window or door so that the sizes of the framing units will vary.

It is therefore an object of the present invention to provide an apparatus for prefabricating a building wall panel. It is another object to provide an apparatus for prefabricating building wall panels that include framing units for one or more windows and/or doors.

It is another object to provide an apparatus for prefabricating a wall panel in which the individual components of the wall are aligned with each other in a substantially horizontal plane and fastened together as certain of the components are moved forwardly within such plane. It is another object to provide an apparatus of the type described including means to momentarily interrupt forward movement of the components while applying a continuous drive force.

Other objects and advantages of the invention will be apparent from the following description, including the drawings in which:

4 FIG. 1 is a representation of a prefabricated wall panel assembled employing the apparatus disclosed herein and including Window and door frame units;

FIG. 2 is a representation, part fragmentary, and part cut-away, of apparatus for prefabricating a building wall panel and depicting various features of the invention;

FIG. 2a is a continuation of the representation of apparatus of FIG. 2;

FIG. 3 is an elevational section of the apparatus shown in FIGS. 2 and 2a and taken generally along line 3-3 of FIG. 2;

FIG. 4 is an elevational sectional view of the apparatus shown in FIG. 3 and taken generally along the line 44 of FIG. 2;

FIG. 5 is a fragmentary side elevational view showing a nailing gun mounted on a portion of the apparatus de-' picted in FIG. 2;

FIG. 5a is a fragmentary rear view of the gun shown in FIG. 5;

FIG. 6 is a fragmentary end view of the apparatus of FIG. 2 and showing the relationship of a stud and a plate in its housing; and

FIG. 7 is a schematic representation of a control means for the apparatus shown in FIG. 2.

With reference to the Figures, the disclosed apparatus in useful in assembling a prefabricated wall panel 10 (FIG. 1) which includes a sill 12, a plate 14 and a plurality of studs 16 extending therebetween. The depicted panel includes a window frame unit 18 comprising studs 16a and 16b, and cross members 20- and 22. This unit is preassembled prior to its introduction to the apparatus disclosed herein. A preassembled door frame unit 24 comprising studs 16c and 16d, and cross member 26 is also shown in FIG. 1. The depicted door frame unit 24 is provided with a removable cross member 28 useful in maintaining the unit square during wall assembly. The disclosed apparatus includes means for incorporating such window and door frame units in the prefabricated wall panel.

Stated briefly, the present apparatus includes means adapted to receive a plurality of studs and align them in a substantially horizontal plane with their lengths substantially parallel to one another and their respective opposite ends in alignment, means to receive and align a sill adjacent one of the aligned ends of the studs, and means to receive and align a plate adjacent the other of the aligned ends of the studs, means to move the studs forwardly along a path in a direction substantially perpendicular to their lengths, and means to fasten thesilland plate to opposite ends of each stud to join the several components into a prefabricated wall panel.

In FIG. 2 there is depicted an apparatus for assembling panels of the type shown in FIG. 1, comprising a frame indicated generally by the numeral 36 which includes a plurality of legs 38 adapted to support a pair of aligned elongated stringers 40 and 42 spaced apart in a substantially horizontal plane above a supporting surface (not shown) with their length dimension defining the length dimension of the frame. The stringers 40 and 42 are connected transversely of the frame by cross members 44 and 46 that extend between the stringers and have their opposite ends welded thereto. The legs of the frame are stabilized as by cross braces 48 and 50 at the rear end of the frame.

As noted above, individual components, for example,

I a sill 52, a plate 54, studs 16, and a window frame unit 18 are received on the frame 36 properly spaced with respect to one another, and fastened together to define the desired prefabricated wall panel. To this end, the depicted frame 38 is provided with beams 56 and 58 extending along the opposite outboard edges 60 and 62 ofthe stringers 40 and 42. In the depicted embodiment, the beam 56 is fixedly mounted, as by welds 64, to the outside edge 60 of the stringer 40 and extends the full length of the frame 36. The beam 56 is provided with a flat upper surface that defines a support surface 66 for receiving one end 68 of the stud 16 disposed across the frame transversely of the frame length. The surface 66 also slidably receives the plate 54 oriented with its length aligned with the length of the frame and approximately perpendicular to the stud length. The vertical level of the surface 66 preferably is slightly higher than the vertical level of the top surface 70 of the adjacent stringer 40 so that the stud l6 will not drag on the stringer when the stud is moved along the length of the frame as will appear hereinafter. The opposite side of the frame 36 is provided with a like beam 58 also having a flat upper surface defining a support surface 72 for the opposite end 74 of the stud l6and for a sill 52. The beam 58 is not fixed to the frame 36, but rather its position is laterally adjustable. To this end, as shown in FIG. 3, the beam 58 is mounted on the ends of a pair of arms 80 and 82 that are telescopically received in the cross beams 44 and 46, respectively, such that, as desired, the beam 58 is movable laterally outwardly from the frame 36 to increase the width dimension between the support surfaces 66 and 72, thereby enabling the apparatus to accept different length studs for assembling panels that have different heights. Lock bolts 84 and 86 threadably fitted in the cross beams 44 and 46, respectively, bear against the arms 80 and 82 and lock them in selected positions.

An elongated housing member 90 is mounted on and in longitudinal alignment with the beam 56 and in perpendicular relationship to the stud 16. This housing 90 includes a first upright elongated panel 92 having its lower side edge 94 joined to the outer edge of the beam 56 and extending upwardly therefrom, a second elongated panel 96 having one of its side edges 98 joined to the upper edge 100 of the first panel 92 and extending downwardly and outwardly therefrom and overhanging less than the full width of the surface 66, of the beam 56 and a third upright elongated panel 102 having its upper edge 104 joined to the lower edge 106 of the second panel 96 and depending therefrom toward the support surface 66 of the beam 56, the several joined panels and the surface 66 of the beam 56 defining an elongated passageway of a size suitable to receive a plate 54, for example a length of 2 by 4 lumber standing on edge as shown in the Figures.

As seen in FIG. 6, the lower edge 108 of the third panel 102 terminates at a vertical height preferably of about one inch above the surface 66 so that the panel is free to move with respect to the surface. The opposite beam 58 is provided with a like, but mirror imaged, elongated housing 110 (FIG. 2) comprising elongated panels 92a, 96a, and a third panel not visible, defining a further passageway providing guidance for sliding movement of a sill 52 in a longitudinal direction along the surface 72 of the beam 58.

In setting up the apparatus for assembling a given wall panel, the distance between the housings 90 and 110 is preset to receive a nominal length stud, for example, a stud 8 feet long. Due to inherent error and lack of precision in cutting studs to length, they normally are not cut to a precise length so that a particular stud may be a fraction of an inch longer than a nominal length. To accommodate such studs of unequal length between the housings 90 and 110, the panels 92, 96 and 102 of the housing 90 and the like panels of housing 110 are made of relatively thin flexible material, such as 1/32 inch thick sheetmetal, so that the housings maintain their integrity for guiding sliding movement of the plate 54 and sill 52 along the surfaces 66 and 72, respectively, in the direction of the frame length and are sufficiently flexible, by reason of their inherent flexibility and the single line of joinder of each housing to its beam so that each housing is movable laterally by a limited amount. This lateral movement of one or both housings by an amount sufficient to accommodate the anticipated maximum error in stud length insures that studs of unequal length fed to the apparatus will be received between the housings with freedom to slide therebetween so that assembly procedure will not be interrupted by a stud that is longer than the nominal length by the slight amount that arises through errors inherent in cutting the studs to length.

In the preferred embodiment, the thickness of the panel 102 of the housing 90 is minimum, consistent with structural integrity of the housing. For example, 1/64 inch thick sheet metal serves satisfactorily for this member. By this means, the ends of the studs are dis posed close to the plate and sill thereby enhancing the efficiency of the nailing operation as will be described.

The second panel 96, 96a of each housing 90, 110 slopes downwardly and inwardly f the frame 36 to define a form of a hopper so that as the studs are fed to the apparatus, they are guided into a position where the ends of the stud rest on the opposite support surfaces 66 and 72 on the beams 56 and 58. This places the stud in position to be moved forwardly within the horizontal plane in which it is supported. Notably, the longitudinal length of each of the housings and is greater than the greatest anticipated width of a door or window frame unit. In this manner, the hopper defined by the housings 90 and 110 is of a size sufficient to receive and feed a preassembled door frame unit, for example. to the apparatus in position for forward movement of the unit. The lateral fexibility of the housings has been found particularly useful in connection with incorporating such door or window frame units into a wall panel using the disclosed apparatus due to the ability of such housings to accommodate studs of unequal length that may be present in a preassembled door frame unit.

As noted above, the housing 90 receives and aligns a plate 54 in juxtaposition to the aligned ends of the studs 16. The length of the sill is oriented substantially perpendicular to the length of the studs so that the sill is positioned for joining to the ends of the studs.

The position of the downstream end 112 of the plate when it is placed initially 'in its housing 90 is established by a retractable stop 1.14 disposed in the support surface 66 of the beam 56 at a location spaced from the rear end 116 of the housing 90. Referring to FIGS. 5 and 5a the depicted stop 114 comprises an air cylinder 118 mounted on the underside of the beam 56 and including a piston 120 member extending from the cylinder 118 upwardly through an opening in the beam 56. The piston is spring biased toward its extended position with respect to the cylinder 118. The piston 120 is moved downwardly toward its retracted position by pressurized air admitted to the cylinder 188 through a conduit 122 as will be referred to further hereinafter, and is of a length sufficient to cause it to project above the surface 66, when so extended, to halt forward movement of the plate 54. A like stop 124 is provided in the surface 72 of the other beam 58 to halt forward movement of the sill 52 when it is placed initially within its housing 110 (See FIG. 3).

The studs 16, or a window or doorframe unit, are moved from their feed point forwardly of the frame, that is, in the direction of the frame length, to a nailing station l26'where the plate 54 and sill 52 are joined to the opposite ends of the studs. as by nailing. Forward movement of the studs is accomplished in the depicted apparatus by a pair ofendless chains 128 and 130. one disposed in an upright plane adjacent the inside face of each of the stringers 60 and -82. More specifically, on the inside face 132 of the stringer -80 there is provided a forward sprocket 134 mounted on a stub shaft 136 that is journaled at one of its ends in the stringer -30 such that the sprocket is oriented uprightly. A rear sprocket M0 mounted on a shaft M2 that is journaled in the stringer 40 is provided adjacent the rear end HM of the frame 36. The endless chain 128 traverses the sprockets 134 and 140 and includes a horizontal upper run 146 that is oriented vertically lower than, but in longitudinal alignment with, the upper surface 70 of the stringer 40.

A plurality of lugs 150 are carried by the chain 128. Each depicted lug 15.0 is generally L-shaped, including a first leg 152 and a second leg 154 joined at one of their ends to each other. Each lug 150 is pivotally attached to one side of the chain 128 in an upright plane as by a pin 156 passing through an opening in the lug at the juncture of its arms and received by the chain. Each of the lugs is biased by gravity toward a position wherein its arms 152 and 154 depend downwardly and outwardly from the pivot point. The preferred pivotal position of the lugs when not in the upper run of the chain is shown in FIGS. 2, 3 and 4. Y

A plate 160 is mounted to the face of the stringer 40 and projects horizontally therefrom beneath the upper run 146 of the chain. In addition to supporting the chain 128 in its upper run, this plate serves to maintain each of the lugs 150 in a pivotal position wherein the arm 152 of the lug is directed substantially vertically upwardly. This is accomplished by reason of the edge of the arm 154 of the lug engaging the inclined leading end 162 of the plate 160 as the chain moves the lug forwardly and by such edge sliding along the top surface of the plate 160 as the lug is progressed through the length of the upper run of the chain. During the time the lug is in the upper run, its arm 152 is prevented from pivoting downwardly, thereby maintaining this arm in a vertical position. Upon the lug 150 leaving the upper run 146 of the chain, the arm 154 passes the rear end 164 of the plate 160 and drops downwardly to rotate the arm 152 in a counterclockwise direction to a position out of contact with the stud.

A substantially identical, but mirror imaged, set of sprockets 170 and 172 are mounted ont'he inside face 174 of the stringer 42 opposite the sprockets 134 and 140. The sprocket 170 is mounted on'a stub shaft 173. The sprocket 172, however, is mounted on the shaft 142 which also receives sprocket 140 as noted above. The endless chain 130 is trained around these sprockets 170 and 172 and includes an upper run 176 passing over a plate 178. Lugs 150a of the kind described above are provided on the chain 130. These lugs 150a function in like manner as the previously described lugs 150 so that it will be visualized that as the chains move the lugs through the upper runs of the their respective chains, the lugs each have a vertical arm 152 and 152a, respectively, extending upwardly above the horizontal plane containing the support surfaces 66 and 72. These upstanding arms engage the back side 180 of the stud 16 and move it forward as the chains move. The lugs 150 on the chain 128 are in lateral register with the lugs 150a on the chain 130 and the chains are moved in unison so that each stud is engaged by one lug on each chain to ensure that the length dimension of the stud remains substantially perpendicular to the plate and sill as the stud moves forward. lt will be noted that the use of stub shafts for mounting the front sprockets 134 and 170 permits operator access to the front end of the apparatus to enhance his efficiency in introducing studs and window or door frame 'units to'the apparatus.

As shown in FIGS. 1, 2 and 3, the rear sprockets 140 and 172 about which the chains 128 and 130 are trained are mounted on a common shaft 142 whose opposite ends are jo urnaled in the stringers 40 and 42. Re- 'ferring to FlGS..2, 4 and 7 the shaft 142 is rotated by means of a motor 182 whose drive shaft 184 carries a sprocket 186 that is connected, through the means of a chain 188, in driving relationship to a further sprocket 190 mounted on the shaft 142.

Upon actuation of the motor 182, the chains 128 and 130 are driven in the direction of arrow A (E16. 2) to move the lugs 150 and 150a in the upper runs of the chains in a direction from the front to the rear of the apparatus. The lugs engage successive studs and move them forwardly to a nailing station 126 where the studs 16 are individually joined at their respective ends to the plate 54 and sill 52. This is accomplished in the depicted apparatus by nailing'guns 196, 198, 200, and 202 mounted outboard of the beams 56 and 58. Guns 196 and 198 are aligned with each other across the apparatus and are operated in unison. Similarly the guns 200 and 202 are on opposite sides of the apparatus and are operated in unison] Each nailing gun 196 comprises a body 204 and a nailing trip 206 and is of the air driven type which drives a nail upon the nailing trip 206 contacting a surface that is to receive the nail. One suitable gun is Model SN lll, manufactured by Senco Products. lnc. of Cincinnati, Ohio. Each of the guns, for example. gun 196, is mounted on a slide 208 that extends in cantilevered fashion from the respective beam 56. An air actuated piston-cylinder device 210 serves to move the gun on its slide toward the beam when pressurized air is admitted to the cylinder 214 as through a conduit 216 leading from the cylinder to a source of pressurized air. Retraction of the gun away from its nailing position is accomplished by spring biasing the piston 212 of the device 210 toward'a retracted position within the cylinder 214. When a plate is disposed on the beam 56, as the gun is advanced toward the beam and'plate, its nailing trip 206 engages the plate to actuate the gun to drive a nail through the plate and into the end of a stud. Thereafter, the cylinder is disconnected from the pres surized air to permit retraction of the gun 196 by the.

spring biased piston 212. The guns 196 and 198 on opposite sides of the frame are mounted at a relatively lower vertical level than the guns 200 and 202 so that the first nail at each end of the stud is driven into the lower portion of the stud and the: nails driven by the guns 200 and 202 are put into the upper portion of the stud. The guns 198, 200 and 202 are each reciprocated on respective like slides employing like piston-cylinder devices.

In an operation of the disclosed apparatus for prefabricating a wall panel, individual studs 16 are fed to the apparatus between the housings 'and with their respective longitudinal dimensions; disposed across the apparatus. One suitable material for the studs is 2 X 4 lumber 8 feet long, for example. The studs are preferably fed to the apparatus on edge, that is, one of their narrow sides rests on support surfaces 66 and 72 of the beams 56 and 58. A 2 X 4 plate 54 is slid into the housing 90, coming to a rest with its forward end 112 abutting the stop 114. On the opposite side of the apparatus, a sill 52 is slid into its respective housing 110 until the forward end of the sill comes to rest against its stop 124. Thereafter, the motor 182 is actuated causing the chains 128 and to move their respective lugs and 150a through the upper runs of the chains. As these lugs are moved forwardly, they engage the back side of the stud and slide it in a direction from the front to the rear of the apparatus (see FIG. 1), maintaining thelength of the stud perpendicular to its direction of forward movement.

Upon the stud reaching a location between the ends 112 and 183 of the plate and sill, the stud contacts the spindle of avalve 220 which actuates the nailing guns 196 and 198 to drive a nail through the plate 54 into the end of the stud and a nail through the sill 52 into the opposite end of the stud. Following this nailing operation, forward movement of the stud is continued. It will be recognized that once the ends of the plate and sill have been nailed to the stud and the stops have been withdrawn, further movement of the stud will cause forward movement of both the plate and sill with the stud. As the stud progresses a relatively short distance further toward the rear of the apparatus, the stud contacts the spindle of a second valve 222 to actuate the nailing guns 200 and 202 to add a further nail through the plate to the end of the stud and through the sill to the end of the stud.

As the first stud is moved forwardly, a second stud is placed in the apparatus in the same manner as the first stud and is engaged by the following set of lugs on the chains 128 and 130. The distance between the successive lugs on the chains spaces the studs-apart by a desired distance, for example 16 inches between centers of the studs. The second stud is moved forwardly with the first stud, but trailing the first stud by 16 inches. As the second stud reaches the nailing station it actuates the nailing guns 196 and 198 as did the first stud for joining the second stud to the plate and sill. A second nail is. applied at each end of the second stud in the same manner as referred to above. This procedure of introducing studs to the apparatus and moving them forwardly in spaced apart relation to each other and nailing successive studs to the plate and sill is continued until the desired wall panel has been assembled. Notably, the first nail is applied to the lower portion of the plate or sill. This procedure has been found to prevent rotation of a stud about its longitudinal axis and resultant misalignment thereof.

If desired, a window or door frame unit is interposed between successive studs in the wall panel by feeding the window or door frame unit into the apparatus at the appropriate time. It will be recognized that the spacing between the stud members of the window or door frame unit is unimportant inasmuch as the leading stud of the window or door frame unit will be engaged by a pair of lugs and spaced from the preceeding stud by the desired distance (e.g., l6 inches). The studs of the window or door frame unit will be nailed to the plate and sill as each of these studs passes the nailing station and actuates the valves 220 and 222 to actuate the nailing guns.

Proper positioning of the nails is important to the physical strength and integrity of the resultant wall. Nails applied at a time when there is movement of the plate and/r sill past the nailing gun often results in incomplete nailing or angular entry of the nail. The present inventor provides for accurate and complete nailing by interrupting the forward movement of the studs, sill and plate during each nailing operation. This is accomplished in the drive mechanism for the chains 128 and 130. I

Specifically, the length of the chain 188 that connects the motor 182 to the shaft 142 is chosen to provide appreciable slack in the chain when it is trained.

about the motor sprocket 186 and the sprocket 190 on the shaft 142. When the motor operates to drive the shaft 142 in the direction indicated by the arrow B, the lower run 224 of the chain will be taut and the upper run 226 will be slack. As seen in FlGS. 4 and 7, an idler roller 228 is disposed adjacent the lower run 224 of the chain 188 in position to apply an upward force against the chain when the roller 228 is moved into contact with the chain. Movement of the idler roller into and out of contact with the chain is accomplished by an air actuated, piston-cylinder device 230 whose piston 232 is spring biased in its retracted position within the cylinder 234 to bias the roller 228 out of contact with the cylinder device 230, the roller 228 is moved against the chain to take up' the slack in the chain and cause the chain to go taut in its upper run 226.

Conversely, when the roller is moved away from the chain, the chain goes slack in its upper run. There is a finite period of time required for the chain to .go slack in its upper run following retraction of the roller 228 away from the lower run of the chain. During this period of time, the sprocket 186 on the motor shaft 184 is turning without driving the sprocket 190 on the shaft 142 so that the endless chains 128 and either do not move or move slower than normal during this period of time. This action is used by the inventor to stop" the forward motion of the endless chains 128 and 130, hence stop the forward motion of the studs, at the time the stud is in position for nailing to the plate and sill. This is accomplished by timing the movement of the idler roller 228 into and out of engagement with the chain 188 to correspond with the arrival of a stud at its nailing position. Specifically, compressed air is admitted to the cylinder 234 of the piston-cylinder device 230 to extend the piston 232 and move the roller 228 mounted on the outboard end of the piston into contact with the chain 188 at all times except when a stud is in position for nailing. The timing of the withdrawal of the roller 228 from the chain 188 with the stud position is provided by connecting the pistoncylinder device 230 through appropriate mechanisms to a valve 220 (FIG. 8) which also controls the supply of air to the gun moving means, so that when a stud actuates a set of nailing guns, air to the device 230 is cut off, permitting the roller to be retracted out of contact with the chain 188 as explained above.

A schematic representation of a control system for the depicted apparatus is shown in FIG. 8. In accordance with this control system, pressurized air from a source 240 is con'trollably admitted to the various piston-cylinder devices in accordance with a program that results in individual ones of the piston-cylinder devices functioning in timed relation with each other and with the various desired resultant functions of the apparatus. Specifically, the source of pressurized air 240 is connected to the first and second normally closed valves 220 and 222 by conduit 24!. Valve 220 is connected by conduits 242 and 244 to the piston-cylinder devices 210 and 21011 that move the nailing guns 126 and 198 toward their nailing positions. Similarly. valve 222 is connected by conduits 246 and 248 to the pistoncylinder devices 2101? and 210c that move the nailing guns 200 and 202 toward their nailing positions.

As noted hereinbefore, the pistons 212, 212a. 212!) and 2120 of the piston-cylinder devices 210, 2100. 2141b and 2106 are spring biased toward a retracted po- 9 sition within their respective cylinders 214, 214a, 214b, and 2140 so that the nailing guns are at all times spring biased away from their nailing positions. Actuation of the piston-cylinder devices 210 and 210a to move the guns 196 and 198 to their nailing positions is accomplished by opening valve 220 as by a stud contacting the spindle 243 of valve 220. This action opens valve 220 to admit air to the cylinders 214 and 214a of the devices 210 and 210a, simultaneously moving the respective pistons 212 and 212a, hence the nailing guns, to their nailing positions. Upon movement of the stud past the spindle 243 of valve 220, the valve returns to a closed position, cutting off the air supply to the piston-cylinder devices 210 and 210a, thereby allowing the spring biased pistons to retract the nailing guns. Valve 222 which controls the introduction of pressurized air to the piston-cylinder devices 21% and 210C by conduits 246 and 248 is deposed downstream from valve 220 (for example about 8 inches) so that as the stud is moved further along its path it contacts the spindle 245 of valve 222, opening this valve to admit air to the cylinders 214b and-214c of the devices 21% and 210C, thereby extending the pistons 212b and 2126 of these devices to move the nailing guns to their respective nailing positions. After the stud has moved past the spindle 245, valve 222 closes, shutting off the air supply to the. cylinders 214b and 214e, thereby allowing the spring biased pistons 212b and 2120 to retract the nailing guns.

The piston-cylinder device 230 that controls the slack in the chain 188 trained about the sprockets 184 and 190, hence controls the momentary interruption in the forward movement of the chains 128 and 130, is actuated at the same time as the stud movement actuates the respective pairs of nailing guns. This is accomplished by connecting the actuation mechanism of the device 230 to the conduits 244 and 248 that supply pressurized air to the guns. Specifically, the conduit 244 leading to the guns 196 and 198 is connected by a conduit 250 to a selector valve 252. The conduit 248 leading to the guns 200 and 202 is connected to the selector valve 252 by a conduit 254. The construction of the selector valve is such that when pressurized air from either of conduits 244 or 248 is directed to the valve 252, the pressurized air, if any, from'the other of the conduits is cut off. In this manner pressurized air from either conduit 244 or 248 is passed through-the valve 252 and, by a conduit 258, to a pressure switch 256 connected in an electrical lead 260 leading from a source of electrical energy to a solenoid 262. A second electrical lead 264 is connected between the electrical source and the solenoid to complete a circuit. The solenoid 262 is operatively connected to a normally open valve 266 interposed in a conduit 268 leading from a source of pressurized air 270 to the cylinder 234 of the piston-cylinder device 230. By this means, when a stud passing over the spindle of either of the valves 220 or 222 actuates either of these valves to admit airto either of conduits 244 or 248, the pressure switch 256 is actuated to activate the solenoid 262 to close the valve 266 and cut off the air supply to the cylinder 234 of the device 230. This permits the spring biased piston 232 to retract within the cylinder 234 and withdraw the roller 228 from the chain 188, resulting in the transfer of the slack in chain 188 from its bottom run 224 to its upper run 226, hence momentary interruption of the forward movement of the studs during nailing.

The stops comprising the pistons and 1200 of the piston-cylinder devices 114 and 124, respectively, are

spring-biased in their extended positions. The cylinders 118 and 118a of the devices 114 and 124 are connected by a conduit 280 to a valve 282 adapted to admit pressurized air from the source 240 to the cylinders 118 and 1180. A normally open valve 284 interposed in a conduit 286 leading from the source 240 to the valve 282 serves to position the spool of the valve 282 such that when the valve 284 is open air is supplied to the cylinders 118 and 118a and the stops are down. Prior to positioning a plate and sill in the apparatus, valve 284 is manually closed. This allows the stops to raise. The valve 282 is further connected by a conduit 288 to the conduit 242 leading from the valve 220 to the nailing guns 196 and 198. Thus, when valve 284 is manually closed, the air is cut off from the cylinders 118 and 118a to permit the stops 1 20 and 1200 to pop up. When released, valve 284 returns by spring action to its normally open position but the design of valve 282 is such that air, remains cut off from the cylinders 118 and 118a. Thereafter, when valve 220 is actuated, pressurized air is admitted to the right side of the valve 282. This action admits air to the cylinders 118 and 118a, lowering the stops 120 and 120a. These stops remain lowered until valve 284 is again actuated manually. When it is desired to retract the pistons 120 and 120a upon start-up of the apparatus, manual actuation of the valve 284 is required as noted above.

Pressurized air from a source 290 is provided to each of thenailing gunsl96, 198, 200 and 202 through conduits 292, 294, 296 and 298. This air provides the force used by the gun for driving the nails.

While preferred embodiments of the present invention have been illustrated and described, it will be obvious to those skilled in the art that changes and'modifications may be made therein without departing from the invention in its broader aspects. For example, whereas the illustrated slack transfer mechanism is preferred for interrupting the forward movement of the studs, other means may be used to accomplish the result, but each such other means has disadvantages. Partic ular features of the invention are defined in the appended claims.

What is claimed:

1. Apparatusfor assembling a wall panel from a plurality of individual components including a plate, a sill and a plurality of studs comprising a frame disposed substantially horizontally above a supporting surface and adapted to receive said plurality of components, said frame including oppo sitely disposed support members aligned with each other in a horizontal plane and defining respective elongated surfaces adapted to support the opposite ends of a plurality of studs extending transversely between said support members for sliding movement therealong, an elongated channel member disposed laterally outside of and aligned with each of said support members, said channel member having its entrance end located adjacent one end of said support member and terminating short of the other end of said support member and comprising a first upright elongated panel having its bottom side edge joined to said support member adjacent the outer side thereof, a second elongated panel disposed in juxtaposition and parallel to said first panel and having one of its side edges joined to the top side edge of said first panel and extending outwardly and downwardly from said top side edge of said first panel and inwardly of said frame to define an acute angle between said panels, and a third elongated panel disposed in juxtaposition and parallel to said second panel and having one of its side edges joined to the lower sideedge of said second panel and extending downwardly therefrom toward said elongated surface on said support member and terminating above said surface whereby said third panel is disposed in a generally upright plane above said surface and is movable with respect to said surface in a direction generally laterally of the length of said surface, said panels and that support member to which they are joined defining an elongated passageway for receiving a plate or sill thereto,

stop means associated with each of said elongated surfaces at the exit end of its respective associated channel member for stopping sliding movement of said plate or sill within said passageway when said plate or sill contacts said stop means whereby a plate in one of said channel members is positioned substantially parallel to a sill in the other of said channel members and spaced apart laterally from such sill by the distance separating said channel members and with their leading ends aligned along a line transverse of said frame,

a plurality of endless means oriented in respective upright planes each of which is located laterally inwardly and aligned longitudinally with one of said elongated surfaces, each of said endless means being adapted to traverse a path including a horizontal upper run extending substantially parallel to its adjacent elongated surface, said upper run extending beyond both ends of said elongated surface of said support member,

horizontal planar support means disposed beneath said upper run,

a plurality of lug means joined to each of said endless means for. travel therewith, each of said lug means including a first elongated arm means and a further elongated arm means joined to one end of said first arm means and extending therefrom at a generally right angle, each of said lug means being pivotally connected to said endless means at the juncture of said firstand further arm means with one of said arm means being slidable on said horizontal planar support means beneath said upper run of said endless means when said lug means is in said upper run,

the other of said arm means of each of said lug means extending upwardly when in said upper run of its respective endless means to engage the backside of a stud supported at its opposite ends on said elongated surfaces of said support member, said plurality of lug means on one endless means being in register with said plurality of lug means on the other endless means, 7

drive means for propelling each of said endless means along its path whereupon said stud is moved forwardly as said plurality, of endless means move through their respective upper run,

a plurality of fastener applicators disposed outwardly and on opposite sides of said frame means at locations adjacent each of said stop means and adapted to fasten said plate and sill to opposite ends of said stud,

means adapted to actuate said fastener applicators substantially simultaneously when a stud is in position between said plate and sill and aligned with said fastener applicators, and

means adapted to suspend the forward movement of said plurality of endless means at the time of actuation of saidfastener applicators.

2. The apparatus of claim 1 wherein said drive means for said plurality of endless means includes a first sprocket driven by a motor means, a second sprocket connected in driving relation with said plurality of endless means, chain means trained about said first and second sprockets, said chain means beingslack'about said sprockets and including upper and lower runs, and means adapted to engage said chain means in its lower run to tighten said chain about said sprockets at intervals of time correlated with the nonarrival of a stud at a position between opposed ones of said fastener applicators.

3. The apparatus of claim 1 in which said bottom edge of said third panel of each of said channel members terminates at a vertical height of about one inch above said support surface of said elongated member.

4. The apparatus of claim 1 wherein said horizontal planar support means disposed beneath the upper run of each of said endless means terminates at its rear end short of said upper run whereby each of said lug means such nail. 

1. Apparatus for assembling a wall panel from a plurality of individual components including a plate, a sill and a plurality of studs comprising a frame disposed substantially horizontally above a supporting surface and adapted to receive said plurality of components, said frame including oppositely disposed support members aligned with each other in a horizontal plane and defining respective elongated surfaces adapted to support the opposite ends of a plurality of studs extending transversely between said support members for sliding movement therealong, an elongated channel member disposed laterally outside of and aligned with each of said support members, said channel member having its entrance end located adjacent one end of said support member and terminating short of the other end of said support member and comprising a first upright elongated panel having its bottom side edge joined to said support member adjacent the outer side thereof, a second elongated panel disposed in juxtaposition and parallel to said first panel and having one of its side edges joined to the top side edge of said first panel and extending outwardly and downwardly from said top side edge of said first panel and inwardly of said frame to define an acute angle between said panels, and a third elongated panel disposed in juxtaposition and parallel to said second panel and having one of its side edges joined to the lower side edge of said second panel and extending downwardly therefrom toward said elongated surface on said support member and terminating above said surface whereby said third panel is disposed in a generally upright plane above said surface and is movable with respect to said surface in a direction generally laterally of the length of said surface, said panels and that support member to which they are joined defining an elongated passageway for receiving a plate or sill thereto, stop means associated with each of said elongated surfaces at the exit end of its respective associated channel member for stopping sliding movement of said plate or sill within said passageway when said plate or sill contacts said stop means whereby a plate in one of said channel members is positioned substantially parallel to a sill in the other of said channel members and spaced apart laterally from such sill by the distance separating said channel members and with their leading ends aligned along a line transverse of said frame, a plurality of endless means oriented in respective upright planes each of which is located laterally inwardly and aligned longitudinally with one of said elongated surfaces, each of said endless means being adapted to traverse a path including a horizontal upper run extending substantially parallel to its adjacent elongated surface, said upper run extending beyond both ends of said elongated surface of said support member, horizontal planar support means disposed beneath said upper run, a plurality of lug means joined to each of said endless means for travel therewith, each of said lug means including a first elongated arm means and a further elongated arm means joined to one end of said first arm means and extending therefrom at a generally right angle, each of said lug means being pivotally connected to said endless means at the juncture of said first and further arm means with one of said arm means being slidable on said horizontal planar support means beneath said upper run of said endless means when said lug means is in said upper run, the other of said arm means of each of said lug means extending upwardly when in said upper run of its respective endless means to engage the backside of a stud supported at its opposite ends on said elongated surfaces of said support member, said plurality of lug means on one endless means being in register with said plurality of lug means on the other endless means, drive means for propelling each of said endless means along its path whereupon said stud is moved forwardly as said plurality of endless means move through their respective upper run, a plurality of fastener applicators disposed outwardly and on opposite sides of said frame means at locations adjacent each of said stop means and adapted to fasten said plate and sill to opposite ends of said stud, means adapted to actuate said fastener applicators substantially simultaneously when a stud is in position between said plate and sill and aligned with said fastener applicators, and means adapted to suspend the forward movement of said plurality of endless means at the time of actuation of said fastener applicators.
 2. The apparatus of claim 1 wherein said drive mEans for said plurality of endless means includes a first sprocket driven by a motor means, a second sprocket connected in driving relation with said plurality of endless means, chain means trained about said first and second sprockets, said chain means being slack about said sprockets and including upper and lower runs, and means adapted to engage said chain means in its lower run to tighten said chain about said sprockets at intervals of time correlated with the nonarrival of a stud at a position between opposed ones of said fastener applicators.
 3. The apparatus of claim 1 in which said bottom edge of said third panel of each of said channel members terminates at a vertical height of about one inch above said support surface of said elongated member.
 4. The apparatus of claim 1 wherein said horizontal planar support means disposed beneath the upper run of each of said endless means terminates at its rear end short of said upper run whereby each of said lug means is freed to pivot out of contact with a stud being moved forwardly along said frame means.
 5. The apparatus of claim 1 wherein each of said fastener applicators comprises a pneumatically powered nailing gun which is actuated to drive a nail upon contact of said gun with a surface intended to receive such nail. 